Concrete pipe making apparatus



July 21, 1964 sT 3,141,222

CONCRETE PIPE MAKING APPARATUS Filed Feb. 4, 1963 2 Sheets-Sheet l INVENTOR HARRY STEIRO ATTORNEYS July 21, 1964 H. STEIRO 3,141,222

CONCRETE PIPE MAKING APPARATUS Filed'F'e b. 4, 1965 2 Sheets-Sheet 2 INVENTORZ HARRY STEIRO' ATTORNEYS United States Patent ()fiice 3,141,222 Patented July 21, 1964 3,141,222 CONCRETE PEPE MAKING APPARATUS Harry Steiro, 3725 Lexington Ave, Madison, Wis. Filed Feb. 4, 1963, der. No. 255,826 3 Qlaims. (Qt. 2530) This invention relates to apparatus for making large concrete pipe, such apparatus being of the type that utilizes an inner core mold which is axially strippable from the finished pipe in a downward direction.

The present invention is in the nature of an attachment for that type of apparatus shown in my US. Patent Number 3,047,929, issued on August 7, 1962, and entitled Concrete Pipe Making Apparatus. This apparatus is capable of producing very large pipe, and the loading and distribution of material into the molds have been a problem, as can be appreciated when it is realized that it is not uncommon to load approximately one ton of material per minute into the annular space between the concentric inner and outer molds.

One aspect of the present invention relates to a mechanical distributor for apparatus of the above type, which distributor is rotatably mounted on the inner core mold and which serves to positively and evenly distribute the mix material around in the annular space between the concentric molds, thereby reducing waste and greatly increasing production rates.

Furthermore, in this type of apparatus, during the time the material is being vibrated and settled in the molds, the inner mold may be reciprocated slightly by its hydraulic cylinder, so as to trowel the inner surface of the pipe being made, to thereby improve the interior finish of the pipe. For certain use of this large pipe, however, it has been found desirable to further improve or increase the smoothness of the interior cylindrical surface of the pipe.

Accordingly, another aspect of the present invention relates to a radially shiftable power troweler which may be attached to the above-mentioned mechanical distributor. This power troweler is urged by centrifugal force against the inner surface of the pipe and with a force proportional to the speed of rotation of the troweler; thereby, the amount of troweling force may be varied as desired. As the inner core mold is stripped downwardly from the pipe, this troweler located on top of the core mold acts to smoothly finish the entire inner surface of the pipe.

These and other objects and advantages will appear more fully hereinafter as this disclosure progresses, reference being had to the accompanying drawings, in which:

FIGURE 1 is a vertical, sectional view through apparatus embodying the present invention, certain parts being shown as broken away or removed for clarity in the drawmgs;

FIGURE 2 is a bottom view of the distributor head and taken along line 2-2 in FIGURE 1, but on an enlarged scale;

FIGURE 3 is a fragmentary sectional view taken along line 3-3 in FIGURE 2;

FIGURE 4 is a fragmentary perspective view, generally from above the inner mold and showing the troweler attached to the distributing arm, but not fully out in the radial direction, and

FIGURE 5 is a fragmentary plan view of the FIGURE 4 showing, but on a reduced scale.

Referring in greater detail to the drawings, a large pit It) is formed below the level of the floor F, and it is into this pit that the inner core mold I and the outer mold O can be lowered after the pipe P is completed, to thereby fully expose the finished pipe at the door level for immediate conveyance elsewhere. The pipe is supported on the stationary support ring R which is fixed to the upper ends of the support columns 12. The columns are rigidly fixed to the base member 13, and are located between the inner and outer molds when the latter are retracted downwardly into the pit.

A pair of large hydraulic cylinders are rigidly fixed in the pit to the channel iron braces 16. The piston rods 17 of these large cylinders are secured to the outer mold O by the braces 18 and are extendable from their cylinders to raise the outer mold as shown in FIGURE 1.

A large central hydraulic cylinder 20 is fixed at its lower end to base 13 and its piston rod 21 is rigidly fixed at its free end to the inner mold I by the rigid cross brace 22.

Appropriate hydraulic conduits (not shown) are connected to the ends of the double acting cylinders 15 and 20, and to suitable hydraulic pressure source and controls (not shown). If a more complete description of the structure and operation above referred to is deemed to be either necessary or desirable, reference may be had to the above-mentioned patent.

The inner core mold I has a flat top comprised of a sheet steel plate rigidly secured in any suitable manner, as by welding or by bolt means Ella, to the upper end of the mold. A generally rectangular and removable center plate 31 is inserted in a complementary opening 31a in the top 30 and supported therein by lugs 32 which are welded on the underside of the top 30 and extend partially beneath the plate 31. Plate 31 and top 30 are flush along their top surfaces; and bolt means 3% extend through the lugs and plate 31 to rigidly but detachably hold the plate in the central portion of the top.

Plate 31 forms part of a distributor head DH, which also includes a central shaft 33 extending through plate 31 and having a sprocket 34 secured adjacent its lower end beneath the top 39. The shaft is rotatably driven through its sprocket by an endless chain 35 from a sprocket 36 of a hydraulic motor 37. Motor 37 provides a power means and is rigidly secured to plate 31, and shaft 33 is rotatably mounted in the bearings 38 rigidly fixed to the lower side of the plate 31. Flexible conduits C and C1 extend downwardly from the motor for connection to the hydraulic system (not shown) and act as supply and exhaust lines for the fluid of the motor to which they are detachably connected in the conventional coupling manner.

The upper end of shaft 33 forms a quick detachable connection with an outwardly extending distributing arm 40 which extends in radially opposite directions from the shaft and at each end terminates short of the diameter of the inner core. The arm is shown as being a straight flat blade which is positioned in a vertical direction on one of its longitudinal edges. The upper end of shaft 33 has a vertical slot 42 in which the arm is detachably held captive by a removable pin means 43 which extends through the shaft and arm.

The motor 37, the bearing mountings for the shaft, and the drive connection between the motor and shaft are all located on the underside of the top and are protected by it from the concrete mix which is dumped onto the flat top of the inner mold.

The above arrangement provides a unitary distributor head which can be lifted out of its complementary opening in the top 3! and replaced in other inner core molds (not shown) of different diameters, as needed.

When the apparatus is in the position shown in FIG- URE 1, the mix material M is deposited (for example by automatic conveying equipment as shown in said Patent Number 3,047,929) on the top of the inner core mold at a rapid rate. As this material is being deposited, the motor 37 rotates the distributor arm 40 which acts to distribute the material equally around the top and simultaneously pushes it outwardly into the annular space S between the inner and outer molds. This loading and distributing process is continued until the molds are filled, and during which time vibrators V act to rapidly settle the no-slump concrete into the concentric molds.

The above described mechanical distributor insures continual and even distribution of the material as the latter is dumped at a considerable rate onto the top of the inner core. No build of material occurs to spill over the sides of the apparatus, and the time of loading and labor required has been substantially reduced over prior apparatus.

After the filling of the molds and settling of the concrete in the forms, the same distributor head, without adjustment is used to guidingly support a power troweler PT, now to be described.

The power troweler PT is mounted on the arm 40, preferably by anti-friction rollers (to be described) so as to insure free radial movement of the troweler on the arm due to centrifugal force, and a troweling force which is proportional to rotational speed of the troweler. In other words, the rollers act to prevent binding between the arm and troweler and insure proper and controllable force against the inner surface of the pipe.

The power troweler includes a support frame including a horizontal support member 50 to which are welded the four outwardly extending rods 51. A troweling shoe 52 is welded to the outer ends of these rods, and is vertically disposed, being curved or of arcuate form when viewed in plan, so as to closely complement the inner wall of the pipe P against which it is urged into troweling engagement.

Preferably, the shoe is curved on a lesser radius than the internal radius of a pipe against which it bears, so as to provide clearance between the pipe and both the front and rear ends of the shoe, in respect to direction of movement of the shoe. This provides good troweling action regardless of play or looseness in the parts, and prevents gouging of the inside of the pipe.

Referring in detail to the above-mentioned rollers, they are arranged on opposite sides of the arm 40 and in spaced apart relationship on each side, so as to embrace the arm therebetween and stabilize the troweler with respect thereto. More specifically rollers 61 to 68, inclusive are rotatably mounted in pairs on their respective shafts 71 to 74 inclusive which are rigidly secured to the support member 50 and extend downwardly therefrom. Thus two pair of rollers are provided for bearing against each side of the edgewise disposed flat arm 40. Furthermore, the rollers on each side are spaced apart radially and vertically for good stability of the troweler.

The weight of the troweler is also supported on the arm to insure free movement by the two radially spaced rollers 80 and 31 which are rotatably mounted on the support member 5%, and rest on and run along the top edge of the arm. The lower edge of the troweling shoe preferably does not slide on the top of the inner mold.

The troweler PT can be easily attached to the arm 40 simply by setting it thereover, and no fastening means are required. The troweler is urged by centrifugal force along the arm and against the pipe with a degree of pressure determined by the rotational speed of the arm, which the operator can closely control. The troweling action starts at the top of the pipe and the entire length is d troweled as the inner mold is stripped downwardly, thus imparting an exceptionally good finish to the pipe interior.

Various modes of carrying out the invention are contemplated as being within the scope of the following claims particularly pointing out and distinctly claiming the subject matter which is regarded as the invention.

I claim:

1. Concrete pipe making apparatus comprising vertically positioned and concentric outer and inner molds that define an annular space therebetween into which lowslump concrete mix is poured to form a pipe, means for vertically shifting said inner mold in a downward direction to strip it from the pipe, a top across the upper end of said inner core, a distributor head mounted centrally on said top and having an outwardly extending distributing arm mounted for rotation around said top to thereby push mix outwardly and into said annular space, said arm having an outer end which terminates within the diameter of said inner mold, said head also having power means for rotating said arm, said power means located beneath and attached to said top and having a driving connection to said arm.

2. Concrete pipe making apparatus comprising vertically positioned and concentric outer and inner molds that define an annular space therebetween into which lowslump concrete mix is poured to form a pipe, means for vertically shifting said inner mold in a downward direction to strip it from the pipe, a top across the upper end of said inner core, a distributor head removably mounted centrally on said top and including a plate detachably mounted on said top, a vertical shaft rotatably mounted on said plate, power means mounted on said plate and having a driving connection with said shaft for rotating the latter, and a distributing arm located within the diameter of said inner mold and connected with said shaft and extending generally horizontally across the top to push mix outwardly into said annular space as said arm rotates around said top.

3. Apparatus as defined in claim 2 further characterized in that said power means and driving connection are located on and attached to the underside of said plate.

4. Concrete pipe making apparatus comprising vertically positioned and concentric outer and inner molds that define an annular space therebetween into which lowslump concrete mix is poured to form a pipe, means for vertically shifting said inner mold in a downward direction to strip it from the pipe, a top across the upper end of said inner core, a plate removably and rigidly mounted generally centrally on said top, a vertical shaft rotatably mounted on said plate and located centrally in respect to said top, a fluid motor secured to the underside of said plate and having a driving connection with said shaft, and a distributing arm detachably secured to said shaft and extending across said top for rotation therearound to push mix into said space, the outer end of said arm terminating within the diameter of said inner mold.

5. Concrete pipe making apparatus comprising vertically positioned and concentric outer and inner molds that define an annular space therebetween into which lowslump concrete mix is poured to form a pipe, means for vertically shifting said inner mold in a downward direction to strip it from the pipe, a top across the upper end of said inner core, a distributor head mounted on said top and having a radially extending distributing arm mounted for rotation around said top to thereby push mix outwardly and into said annular space, said head also having power means for rotating said arm; and a power troweler mounted on said arm and radially shiftable thereon for troweling engagement with the inner surface of said pipe as said troweler is rotated therein by said arm and said inner mold is stripped of downwardly.

6. The apparatus as set forth in claim 5 further characterized in that said troweler has a vertically positioned troweling shoe of curved cross section when viewed in 5 plan to thereby closely complement the inner surface of the pipe against which it is urged in troweling engagement.

7. Concrete pipe making apparatus comprising vertically positioned and concentric outer and inner molds that define an annular space therebetween into which lowslump concrete mix is poured to form a pipe, means for vertically shifting said inner mold in a downward direction to strip it from the pipe, a top across the upper end of said inner core, a radially extending arm rotatably mounted on said top, power means for rotating said arm, and power troweler mounted on said arm for shifting in a radial direction, said troweler including a troweling shoe engageable with the inner surface of said pipe to effect a troweling action thereon as said arm rotates and said inner mold is stripped downwardly.

8. The apparatus set forth in claim 7 including antifriction rollers on said troweler for guiding engagement with and support on said arm.

References Cited in the file of this patent UNITED STATES PATENTS 1,473,969 Nichols Nov. 13, 1923 1,961,981 Pechstadt June 5, 1934 2,091,385 Trickey Aug. 31, 1937 2,165,671 Ward July 11, 1939 2,320,714 Boyle June 1, 1943 2,800,700 Clement July 30, 1957 3,047,929 Steiro Aug. 7, 1962 FOREIGN PATENTS 128,815 Sweden July 11, 1950 

1. CONCRETE PIPE MAKING APPARATUS COMPRISING VERTICALLY POSITIONED AND CONCENTRIC OUTER AND INNER MOLDS THAT DEFINE AN ANNULAR SPACE THEREBETWEEN INTO WHICH LOWSLUMP CONCRETE MIX IS POURED TO FORM A PIPE, MEANS FOR VERTICALLY SHIFTING SAID INNER MOLD IN A DOWNWARD DIRECTION TO STRIP IT FROM THE PIPE, A TOP ACROSS THE UPPER END OF SAID INNER CORE, A DISTRIBUTOR HEAD MOUNTED CENTRALLY ON SAID TOP AND HAVING AN OUTWARDLY EXTENDING DISTRIBUTING ARM MOUNTED FOR ROTATION AROUND SAID TOP TO THEREBY PUSH MIX OUTWARDLY AND INTO SAID ANNULAR SPACE, SAID 